Animal-shears



C. M. PALMER.

ANIMAL SHEAHS.

APPLxcATloN FILED SEPT. 3, 191s.

Patented Aug. 23, 1921.

UNITED STATES PATENT OFFICE.

ANIMAL-SHEARS.

Specication of Letters Patent.

Patented Aug. 213, 1921.

Application filed September 3, 1918. Serial No. 252,385.

To all 'w wm t may concern?,

Be it known that I, Cnns'rnu Moses PALMER, a citizen of the UnitedStates of America, and a resident of Aurora, county of Kane, and Stateof Illinois, have invented certain new and useful Improvements inAnimal-Shears, of which the following is a specilication.

My invention relates to improvements in that class of animal shearingmachines in which the oscillating cutter lever is mounted at a liXedangle on a pivot shaft having rotative bearing in the upper and lowerwalls of the shear casing or frame, and a hand operated tension screwfor adjusting the tension pressure on the movable cutter and the objectof my present invention is to provide a means of variably increasing theadjusted tension pressure upon the movable cutter in proportion to thevarying cutting resistance of the haii: or wool of the animal beingshorn.

In the device illustrated in the accompanying drawings, the hereindescribed improvement-s are shown embodied in animal shears of that typecovered by U. S. Patents Nos. 877,517 and 1,282,459 issued to me onJanuary 28th, 1909, and October 22nd, 1918, both of which illustrate, ahand operated tension screw for adjusting the tension pressure on themovable cutter, and also a means of equalizing said tension pressureupon the different teeth of the movable cutter, while in addition to theabove, my present invention provides a means by which the adjustedtension pressure on the movable cutter is variably and automaticallyincreased by and in proportion tothe varying cutting resistance of thehair or wool of the animal being shorn.

Most all shearing machines have a hand operated tension screw which isnotched to provide a vertical adjustment of from two to .fivethousandths of an inch, to provide an increased tension pressure as thecutters become dulled by use, and it requires about an equivalentincrease of tension pressure to cut the heavier wools as smoothly as thelighter wools of an animal, and I find by experiments that I can producesuch required increase of tension pressure automatically, in that classof shearing machines described by making one or both of the pivot shaftbearings from four to ten thousandths of an inch larger in diameter thanthe corresponding part of the pivot shaft, the

amount of excess play required being determined largely by the design ofthe machine.

The usual mechanical allowance for such bearings being from one to twothousandths of an inch.

In using the ordinary shearing machine, the operator usually sets thetension only tight enough to cut the lighter wools smoothly, with theresult that the heavier wools are partly broken or torn off leaving aruffled and ragged appearance, or if the tension is set tight enough tocut the heavier wools smoothly, the excessive friction causes themachine to heat and dulls the cutters very quickly. In operating ashearing machine embodying my present invention the tension need only beset tight enough to cut the lighter wools smoothly, the tension pressureon the movable cutter heilig automatically increased by the cuttingresistance of the heavier wools which are thereby cut smoothly, and themachine operates with a comparatively light empty.

An illustrative embodiment of this invention is shown in theaccompanying drawings, in which- Figure .l isa plan of a pair of animalshears embodying this invention.

Fig. 2 is longitudinal sectional elevation same taken on line 2 2 ofFig. l.

F ig. 3 is a fragmentary sectional detail taken on a line 3-3 of Fig. 2.

Fig. il is substantially a section taken on line 4l-4 of Fig. 2;

Fig. 5 is a lragmentary view, partly in section, showing a modifiedarrangement of tension while running the shaft in its lower bearing;

F ig. 6 is a bottom view of the parts shown in Fig.

Similar numerals refer to similar parts throughout the several views.

Secured to the forward end of the casing or frame l is the comb or fixedcutter 6 in contact with which the movable cutter 5 is adapted to beoscillated by the lever 3 which is centrally mounted on a pivot shaft 2which is rotatively journaled in bushings 7 and 8 having screw' threadedconnection respectively with the upper and lower walls of the frame 1.

The pivot shaft 2 has upper and lower cylindric portions which haverotative bearing respectively with the bushings 7 and 8 before referredto, and extends through a vertical opening 11 in said cutter lever, an

annular shoulder 9 and a flat sided shoulder are formed on the vshaftnear the middle thereof but spaced apart axially so that when the shaft2 and the lever 3 are assembled the shoulder 9 will fit in the taperedbore 11 at ak point below the longitudinal center o-f the lever 3 andtheshoulder 10 will contact with a flattened surface or shoulder 12 formedon the lever 3 above said longitudinal center, forming la verticallyvseparated two point Contactv between the said shaft and lever tomaintain them at a fixed angle, and the latter is adapted to rockslightly relatively to the shaft, so that the forked end of the leverwill bear uniformly on the movable cutter 5. Said lever 3 is provided atits rear end with a vertical socket 14 in which operates a ball4`mounted on a. Vcrank pinvextending forwardly and eceentrieally fromthe driving crank shaft 15, whereby oscillato motion is given tosaidcutter lever and e cutter carried thereby, through the rotarylaction ofsaid shaft. Y v

yThe tension exerted on said cutter lever to maintain the movable cutterin proper relation to the fixed comb, or cutter isef'fected through thepivot shaft'2, and the construetion and arrangementof the parts are suchthat the oscillatory cutter lever is maintained at all times atafixedangle to the pivot shaft 2 Vand all tension applied thereto is exertedoni-the front end of thelever to hold the f movable cutter against thefixed cutter, while the rear end ofthe lever is freel from engagementwith a friction surface. The construction of the parts, however -is suchthat the cutter leveris free to rock slightly on its longitudinal axisto permit itito properly adjust'itself and the cutter carried thereby.to maintain a uniform contact of the movable `cutter with 'the fixedcomb Orcutter as has been fully set forth and claimed in my Patent No.877,517, issued January 28th, 1909.

The manually operated tensioning means comprises an internally threadedcap 16 and a pin 17 interposed between the said cap and the shaft 2. Thecap 16 has threaded engagement with'the bushing 7 in axial alinementwith the shaft 2 and is provided with a notchedfiange'lS with which thespring 19 2 and rests upon a ball 23 seated in the bore 22.'- Thediameter of the pin v17 is less than that of the bore 22 and by reasonofthe pivetal `mounting'of the pin 17 there is the least .possibleamountof resistance to the shifting of the shaft 2 which will be more fullyexplained; f v

f'Te provide a means' of automatically increasing the adjusted tensionpressure on the movable cutter, as is required to cut the heavier woolsof an animal smoothly, either the upper bearing 7 or the lower bearing 8or both bearings are formed from four to ten thousandths of an inchlarger in diameter than the corresponding party of the pivot shaft2,`the amount of such excess play required depends largely on the designof the machine. It will be understood that it will require less excessplay if provided in both of the bearings than if in one only.

In the device shown in Fig. 2 the upper bearing 7 is formed from sevento ten thousandths of an inch larger in diameter than the correspondingpart of the shaft 2 and the lower bearing 2 is formed with the usualmechanical allowance of from olie to two thousandths of an inch play.

Referring now to Fig. 2 for an explanation as to why the provision of acertain amount of excess play between the pivot shaft and its bearingsaffords the desired automatic increase of tension pressure upon themovable cutter required to cut the heavier wools of an animal smoothly,it will be seen that the shaft with the adjustable tension normal restsat its upper end against the rear face of the bearing in the bushing 7and at its lower end against the front face of the bearing formed in thebushing 8. This condition is due to the fact that the tensioning forceis made effective upon the lever 3 through the medium of the verticallyseparated two point contact of the shaft 2 with the lever 3. The pivotshaft 2 bears upon onlyA a very small are of the bearing surface formedin the bushing 7 having a free space on each side and in front of theshaft as is clearly shown in Fig. 4, allowing the upper end of the shaftto be shifted laterally and thereby forwardly under the infiuence of therotating crank pin and ball 4 which a plies its force to the lever 3 ina lateral irection. The direction ofthe shifting or tilting of the shaftlaterally corresponds at all times to the direction in which the crankpin is at that time applying lateral pressure upon the lever,and thegreater the force applied laterally to the lever due to the cuttingresistance of the hair or wool being cut, the greater the shifting ofthe shaft laterally and forwardly at the upper end, and rearwardly atthe lower end if excess play is provided in the lower bearing, therebyincreasing the tension pressure on the movable cutter in proportion tothe force required to oscillate the said cutter lever.

The usual allowance of play provided in the pivot shaft bearings ofshearing machines of the class described does not produce anycomparative or practical increase of tension, but the greater the amountof excess play provided the greater will be the increase of tension'pressure in proportion to CIK -ried thereby may the cutting resistanceof the hair or wool, and the exact amount of excess play required toprovide the desired increase of tension pressure on the movable cutterto cut the heavier wools of the animal smoothly, will vary indifferently designed machines.

l claim :h

l. A shearing,` machine comprising a easing, a xed comb or cutter, acutter movable en said fixed cutter, an oscillatory cutter lever, apivot shaft having` rotative bearing in the ripper' and lower walls ofsaid casing and non-rotatively engaging between its ends said lever, oneof said pivot shaft bearings formed relatively larger in diameter thanthe corresponding,l part of said shaft, whereby a comparativelyincreased tension may be provided automatically by the op` eration ofthemachine, an adjustable tension screw having,` threaded engagement withsaid casing` in axial alinement with said pivot shaft, a pivot pininterposed between said tension screw and pivot shaft for applyingtension to the lever through said shaft, ineansiwhereby the lever andthe cutter carhave a slight rocking movement with respect to the shaftto permit uniform pressure of the cutter' on the fixed comb, meanswhereby a fixed angle between said pivot shaft and lever is maintained,and means for oscillating said cutter lever.

2. In a shearingr machine, the combination with a casing', a fixed combor cutter, anda cutter movable on said fixed comb, of a pivot shaftjournaled at its ends in the upper and lower walls of said easing, anoscillatory cutter lever mounted at a fixed angle mediate the ends ofsaid pivot shaft, means for applyingv an adjustable tension pressure tosaid lever through said shaft, said pivot shaft bearings relativelylarger in diameter than the corresponding' parts of said shaft whereby acomparatively increased tension may be provided automatically by theoperation of the machine, means whereby the forward end of said leverand the cutter carried thereby may have a slight rocking movement topermit uniform pressure of the cutter on the fixed comb, and `a means ofoscillating said lever.

3. In a shearing machine the combination with a casing', a fixed comb orcutter, and a cutter movable on said fixed comb, of a pivot shaft havingrotative bearing in the upper and lower walls of said casing, anoscillatory cutter lever mounted at a fixed angle, mediate the ends ofsaid shaft, an adjustable tension screw having threaded engagement withthe casing in axial alinement with said pivot shaft, a pivot pininterposed between said tension screw and said pivot shaft, to applytension to the lever through said shaft, said pivot shaft bearingsrelatively larger :in diameter than the corresponding` parts of saidshaft whereby a comparatively increased tension may be providedautomatically while cutting' the hair or wool of' an animal, meanswhereby the forward end of said lever and the cutter carried thereby mayhave a slight rocking movement with respect to said shaft to permituniform pressure of the cutter on the guard plate, and means foroscillating aid lever.

4. In shearing machines, the combination with a casing, a fixed comb,and a cutter movable on said fixed comb, of a pivot shaft havingrotative bearing),r in the upper and lower walls of said casing, anoscillatory cutter lever mounted at a fixed angle mediate the ends ofsaid pivot shaft, an adjustable tension screw having threaded engagementwith said casing in axial alinement with said pivot shaft, a pivot pininterposed between said tension screw and saidshaft to apply tension tosaid lever through said shaft, and means whereby the front end ofv saidlever and the cutter carried thereby may have a slight rockingV movementto permit uniform pressure of the cutter on the fixed comb.

Signed at Aurora this 29 day of Aug.,

CHESTER M. PALMER.

